According to an increase in output of an electric power tool, the level of vibration of the tool has been increased. A contact force of a switch is therefore more necessary than before. As a conventional technique for increasing a contact force, for example, a trigger switch disclosed in Patent Literature 1 is known. The term “contact force” means a force by which a contact of a switch is pressed against the other contact.
As illustrated in (a) of FIG. 10, a trigger switch 100 disclosed in Patent Literature 1 includes (i) a first movable contact 111 which is provided at one end part and (ii) a second movable contact 112 which is provided at the other end part. The trigger switch 100 further includes (i) a movable contact piece 110 configured to turn while being supported at the support member 101, (ii) a slide member 102 configured to slide while pressing a slide surface 113 of the movable contact piece 110 so that the slide member 102 causes the movable contact piece 110 to turn in a seesaw-like pattern, (iii) a first terminal 103 having a first fixed contact 103a, (iv) a second terminal 104 having a second fixed terminal 104a, and (v) a plunger 106 configured to cause the slide member 102 to move horizontally.
As illustrated in (b) of FIG. 10, in a case where the trigger switch 100 thus configured pushes the plunger 106 in, the slide member 102 slides in a rightward direction on the slide surface 113. When the slide member 102 passes a protruding support point 113a provided on the slide surface 113, the movable contact piece 110 turns so that the second movable contact 112 comes into contact with the second fixed terminal 104a. 
As illustrated in (c) of FIG. 10, in a case where the plunger 106 is further pushed in, the slide member 102 further slides in the rightward direction on the slide surface 113. Then, in a case where the slide member 102 reaches a top portion 113b of the slide surface 113 at the movable contact piece 110, the pressing force of the slide member 102 increases. This causes the second movable contact 112 and the second fixed terminal 104a to be firmly in contact with each other.
According to the trigger switch 100 thus configured, the contact force between the second movable contact 112 and the second fixed terminal 104a can be increased so as to improve a vibration resistance.